1. Field of the Invention
The present invention relates to a movable contact for a two-step push-on switch in which first and second switches are sequentially turned ON as a result of a depressing operation, and also to such a push-on switch.
2. Description of the Prior Art
Among two-step push-on switches of this kind, a switch in which first and second movable contacts that are invertable are vertically arranged in two stages (for example, see “Japanese Utility Model Application Laying-Open No. 3-8827”) is improved into a switch in which a single movable contact placed in a case is provided with first and second movable contact portions (for example, see “Japanese Patent Application Laying-Open No. 3-89421” “Japanese Utility Model Publication No. 7-53234” and “Japanese Patent Application Laying-Open No. 11-232962”), whereby the number of parts is reduced, the number of man-hours is reduced, and the switch is thinned.
In the improved movable contact of the single-plate configuration, in order to produce a sufficient sense, a case having molded metal terminals must be disposed, and a countermeasure such as that the peripheral portion of the movable contact is fixed, or that a step is formed in a stationary contact must be further taken. Therefore, there arises a problem in that a sufficient sense is hardly obtained in a case of a flat mounting surface such as the case of a printed circuit board (PCB) or a flexible printed circuit board (FPC).
In a case where a switch is to be configured on a side face of a thin electronic apparatus, the size in the width direction must be reduced. In a movable contact which is circular as a whole, and which has a circular annular peripheral plate portion, a circular center plate portion that is upward inflatingly curved, and a connecting plate portion that connects these plate portions together (for example, see Japanese Utility Model Publication No. 7-53234), when the center plate portion has a large diameter, it is possible to attain a long life period, but the width cannot be decreased. By contrast, when the whole diameter is reduced, the width can be decreased, but a long life period of the center plate portion cannot be attained.
The invention has been conducted in view of the above-discussed problems. It is an object of the invention to provide a movable contact for a two-step push-on switch which can realize an excellent sense and a long life period while decreasing the width, even on a flat stationary-contact forming surface of a printed circuit board, a flexible printed circuit board, or the like, and also to provide a two-step push-on switch.